Impact assessment and uncertainty: perceptions of New Zealand decision-makers

Abstract

Environmental and resource management decision-making can be extremely complex, controversial, ambiguous and difficult. Uncertainty, or the imperfect and inadequate understanding of a system, is an inherent part of decision-making. Impact assessment (IA) is an important tool that is used to evaluate, and inform decision makers of, the likely environmental effects of major proposals. There is widespread recognition of the importance of acknowledging, understanding and managing uncertainty that arises in resource management problems. Despite this, the recognition and treatment of uncertainty in the IA and subsequent decision-making process is often not well handled and in many cases not recognised, managed or taken into consideration. This research aimed to understand how decision-makers recognise the presence of uncertainty, particularly in the effects information, and how uncertainty is managed within the resource consent decision- making in New Zealand. In order to achieve this 104 experienced resource consent decision-makers, who act as internal or independent commissioners, were surveyed. The results suggest that decision-makers’ have varied perceptions of the acceptability of uncertainty, the need for applicants to disclose uncertainty and decision makers to take it into account. The primary cause of uncertainty for decision-makers was poor quality effects information lacking important detail, although conflicting information, inherent uncertainty, and difficulty interpreting certain parts of the Resource Management Act 1991 were also emphasised as other notable sources of uncertainty. Decision-makers manage uncertainty in a variety of different ways, but predominantly used strategies to further understand and reduce uncertainty, rather than strategies to cope with the uncertainty once it has been accepted. Some recognised strategies were not used as frequently as they maybe could be (such as the precautionary principle and adaptive management), while others were used without properly considering the implications. Finally, it seems that the experience and professional background of decision-makers influences the way in which they understand and manage uncertainty. However, these characteristics do not fully explain the diversity in results, and it is likely that there are many other factors influencing decision-makers behaviour. The diversity in decision-makers responses suggests decision- makers are not being given substantive guidance about how to manage uncertainty and that the commissioner accreditation process is not moulding diverse individuals into decision- makers who are able to cope with uncertainty in a consistent manner. They still have a certain level of freedom to respond as they see fit, and are falling back to a large extent on personal perceptions, values, feelings and coping mechanisms, in deciding how to manage uncertainty.